Tool to measure and set angels using calipers or other linear measuring devices

ABSTRACT

This invention provides an angle gauge that, when used in conjunction with a caliper or other linear measuring device, improves both the precision and ease with which angles can be measured and set by allowing the user accurately to measure and set angles in fractions of degrees. Using the gauge, an angle formed by the gauge may be determined or set by reference to the linear distance measured by the caliper. Calculations or tables can be used to convert the linear measurements into the angle setting or measurement with great accuracy, or the capacity to calculate the angle corresponding to the linear measurement can be built (i.e. programmed) directly into the device.

[0001] This application claims priority to U.S. Provisional PatentApplication No. 60/250,314 filed Nov. 30, 2000, entitled “Tool toDetermine Angles Using Calipersor Other Linear Measuring Devices.”

BACKGROUND

[0002] In various manufacturing and technical assembly applications,such as woodworking and metalworking, it is important to accurately setand measure angles to ensure the components of a workpiece, jig ormachine are precisely oriented relative to each other. Currently, thesetting and measurement of angles relies primarily upon variousprotractor devices or sine bars. But protractor devices, such as theruler and protractor head of a combination square, lend themselves toless than precise angular measurements. Such inaccuracy is caused bothby the design of the devices and by operator error. Positioning theprotractor to reflect the correct angle can be difficult, especially tothe unskilled operator. Even if properly positioned, many protractorsare able to measure, at best, one-degree increments. Therefore, an anglesetting or measurement read from a protractor is frequently accurateonly to the nearest degree. Smaller, fractional increments are notavailable. Additionally, differentiating between the one-degreeincrements when the protractor is in use can be difficult, oftentimesleading to inaccurate readings by the user.

[0003] While sine bars are more precise, they are more expensive,complex to use, and require a strong understanding of trigonometry, andthus their enhanced precision can be compromised by user error as well.Therefore, a need exists to provide a device that both enhances theprecision of angle measurements and settings and simplifies the process.Another usable device is described in U.S. Pat. No. 6,148,531, whichconverts linear measurements into angular settings. While versatile,this prior device can be difficult to use with desired accuracy incertain situations and requires manipulation and manual alignment of atleast two different assemblies during use rather than one unifiedassembly.

SUMMARY OF THE INVENTION

[0004] This invention provides an angle gauge that, when used inconjunction with a caliper or other linear measuring device, improvesboth the precision and ease with which angles can be measured and set byallowing the user to accurately measure and set angles in fractions ofdegrees. Using the gauge, an angle formed by the gauge may be determinedor set by reference to the linear distance measured by the caliper.Calculations or tables can be used to convert the linear measurementsinto the angle setting or measurement with great accuracy, or thecapacity to calculate the angle corresponding to the linear measurementcan be built (i.e. programmed) directly into the device.

[0005] The gauge is first mounted on the arms of a caliper. To set aparticular angle, the user locates on the table the distance between thecaliper arms that corresponds to the desired angle and sets and locksthe caliper arms at that distance, which automatically positions thearms or wings of the gauge at the desired angle. Similarly, to measurean angle between two reference structures, the user positions the gaugewings in contact with the reference structures, notes the distance onthe caliper when the gauge is so positioned, and consults the table tolocate the angle measurement corresponding to that distance. Auxiliaryarms may be added to the gauge to provide additional ranges of anglesfor measurement and setting.

[0006] In the angle gauge of this invention, two reference wings arepivotably joined to move through 90 degrees of movement relative to eachother while each wing is coupled to a caliper arm and the caliper armsmove between a fully closed and an open position. An auxiliary rightangle attachment arm may be attached to each wing, in effect adding orsubtracting 90 degrees from the angular relationship between the wings.

[0007] It is an object of the present invention to improve the precisionand ease with which angles can be measured and set.

[0008] It is another object of the present invention to provide a systemthat converts a linear distance into angular measurements.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009]FIG. 1 is a top plan view of one embodiment of the angle gauge ofthis invention positioned on a fully open caliper.

[0010]FIG. 2 is a perspective view of the embodiment of FIG. 1.

[0011]FIG. 3 is an exploded view of the angle gauge shown in FIG. 1.

[0012]FIG. 4 is a top plan view of the embodiment of FIG. 1 in a secondorientation with the caliper partially closed.

[0013]FIG. 5 is a perspective view of the assembly shown in FIG. 4.

[0014]FIG. 6 is a top plan view of the embodiment of FIG. 1 with thecaliper fully closed.

[0015]FIG. 7 is a perspective view of the assembly of FIG. 6.

[0016]FIG. 8 illustrates the embodiment of FIGS. 1-7 in use.

[0017]FIG. 9 is a top plan view of the embodiment of FIG. 1 with a rightangle attachment.

[0018]FIG. 10 is a perspective view of the embodiment of FIG. 9.

[0019]FIG. 11 is a top plan view of the embodiment of FIG. 1 with tworight angle attachments.

[0020]FIG. 12 is a perspective view of the embodiment of FIG. 11.

[0021]FIG. 13 is a table showing corresponding linear and angularmeasurements for use with the embodiment of FIGS. 1-7.

[0022]FIG. 14 is a table showing corresponding linear and angularmeasurements for use with the embodiment of FIGS. 9-10 having one rightangle attachment.

[0023]FIG. 15 is a table showing corresponding linear and angularmeasurements for use with the embodiment of FIGS. 11-12 having two rightangle attachments.

[0024]FIG. 16 is an exploded view of an alternative embodiment of thedevice of the present invention.

[0025]FIG. 17 is a top plan view of the embodiment of FIG. 16 positionedon a fully open caliper.

[0026]FIG. 18 is perspective view of the embodiment of FIG. 17.

[0027]FIG. 19 is a top plan view of the embodiment of FIG. 16 in asecond orientation shown as it would be positioned on a fully-closedcaliper.

[0028]FIG. 20 is a perspective view of the embodiment of FIG. 19 shownon a closed caliper.

[0029]FIG. 21 is a top plan view of the embodiment of FIG. 16 in a thirdorientation with a partially open caliper.

[0030]FIG. 22 is a perspective view of the embodiment of FIG. 21.

[0031]FIG. 23 is a top plan view of the embodiment of FIG. 16 in afourth orientation.

[0032]FIG. 24 is a perspective view of the embodiment of FIG. 23.

[0033]FIG. 25 is a table showing corresponding linear and angularmeasurements for use with the embodiment of FIGS. 16-24.

DETAILED DESCRIPTION OF THE DRAWINGS

[0034] The angle gauge of this invention measures and sets angles withenhanced accuracy using a linear measuring device, such as aconventional digital read-out or dial read-out caliper. While, forpurposes of discussion, the device is shown in use with a digitalcaliper, it may be used with any appropriate linear measuring device.

[0035] FIGS. 1-12 illustrate one embodiment of the angle gauge 10 ofthis invention positioned on the arms 36, 38 of a digital caliper 40.Angle gauge 10 has two protractor wings 14, 16 pivotably attached at acenter pivot 18. A usable pivot structure is illustrated in FIG. 3 wherea center pivot 18 having a threaded connector 20 is received in an axle22, but other suitable pivot arrangements are also usable. Each wing 14,16 is equipped with at least one reference surface 24, 26. Slopingdovetail surfaces 25 and 27 facilitate easy and accurate attachment ofaccessories, such as, for example, a sliding “shoe” (not shown) or rightangle attachments, as discussed later.

[0036] Each wing 14, 16 further has a bracket arm 28, 30 pivotablyattached to the wing 14, 16 with a bracket arm pivot 32, 34 for securingthe wing 14, 16 to an arm 36, 38 of the caliper 40. FIG. 3 illustratesthe bracket arm pivots 32, 34 having a free pivot 41, 42 which is pressfitted into a flange 43, 44. However, any center pivot and bracket armpivot that pivotably connects each wing 14, 16 with its bracket arm 28,30 may be used, and this invention is in no way limited to thosepivoting means illustrated herein.

[0037] Each bracket arm 28, 30 also has an attachment means forattaching the device to the caliper arms 36, 38. While numerousattachment structures may be used, FIGS. 1-12 illustrate attachment ofthe bracket arms 28, 30 to the caliper arms 36, 38 with sleeves 46, 48and screws 50, 52 threaded into the sleeves 46, 48. A caliper arm 36, 38fits into the sleeve 46, 48 of a bracket arm 28, 30 and the screws 50,52 are tightened to bear against and thereby secure the caliper arm 36,38 in the bracket arm sleeve 46, 48.

[0038] The bracket arms 28, 30 are preferably configured so that, whenattached to the caliper arms 36, 38, they do not cover or obstructreference surfaces 35, 37 of the arms 36, 38. For example, in theembodiment of FIGS. 1-12, the bracket arms 28, 30 are offset from thereference surfaces 35, 37. When so positioned on the caliper arms 36,38, the gauge 10 generally does not interfere with translation of thecaliper arms 36, 38 along the caliper 40 or otherwise with use of thecaliper 40 as a linear measuring tool for objects that can fit betweencaliper arms 36 and 38 without also contacting wings 14 or 16 of anglegauge 10. Moreover, the offset bracket arms 28, 30 allow the gauge 10 tobe used at any angle without interference by the caliper, particularlythe depth gauge stem 33. See FIG. 1.

[0039] The gauge 10 may be made from a variety of materials possessingsuitable physical properties including structural integrity, including,but not limited to, plastic, steel, and extruded aluminum. Moreover, thedifferent components of the gauge 10 can, but need not, be made from thesame materials.

[0040] Using gauge 10, an angle may be determined or set by reference toa linear distance as indicated by the caliper 40. Tables 1-3 (portionsof which are reproduced in FIGS. 13-15) are provided for use with thegauge 10. The tables are generated using standard trigonometry andindicate the various angles corresponding to a linear distance. Whilethe tables reflect the distances in 0.01 millimeter (mm) increments,smaller or larger increments may be provided depending on the caliperused and the application. Moreover, the English system may be usedinstead of the metric system. As an alternative or supplement to thetable, a digital caliper or other device may be programmed to calculatean angle from the linear distance using appropriate trigonometricfunctions and display the angular value directly on a readout.

[0041] For purposes of illustration only, the angle gauge 10 shown inthe figures and described here is shown with a 6″ (or 153 mm) digitalcaliper 40. The gauge 10 may be built for use with a number ofdifferent-sized calipers, including 8″ (or 203 mm) and 12″ (or 305 mm)calipers, and other sizes of calipers and other linear measuringdevices. Gauge 10 may also be built as a dedicated angle-measuring gaugewith a dedicated linear measuring assembly substituted for caliper 40.Such a dedicated measuring assembly could have a dial, digital or otherread-out that displays an angular value either indirectly or directly.

[0042] Calibration

[0043] Before use, the gauge 10 may be calibrated as follows:

[0044] 1. Position the reference surfaces 24, 26 against a flat surfaceso the reference surfaces 24, 26 form a 180° angle (see FIGS. 1-2).

[0045] 2. Open the caliper arms 36, 38 until the caliper 40 readsprecisely six inches (or 153 mm) (or in some cases where the calipersetting can be set to “zero” as in digital calipers the caliper may befully extended to whatever the caliper's fully open measurement is) andlock the caliper arms 36, 38 in place.

[0046] 3. Attach each bracket arm 28, 30 to the appropriate caliper arm36, 38 while the reference surfaces 24, 26 remain flat on the underlyingsurface.

[0047] 4. Unlock the caliper arms 36, 38.

[0048] Once the caliper arms 36, 38 are unlocked, the gauge 10 may beused to set and measure angles. In the first embodiment, shown in FIGS.1-8, the gauge 10 is capable of measuring angles between 90°-180°. Foreach linear distance, two corresponding angles are provided in Table 1,primary angle A and supplementary angle S. Primary angle A representsthe angle formed by the reference surfaces 24, 26, and supplementaryangle S represents the supplementary angle of the primary angle A (i.e.180°-A).

[0049] When the caliper arms 36, 38 are in their fully open position asshown in FIGS. 1 and 2 (i.e. D equals 6″), the reference surfaces 24, 26form a primary angle A of 180° and a supplementary angle S of 0°. Whenthe caliper arms 36, 38 are in their fully closed position as shown inFIGS. 6 and 7 (i.e. D equals 0″), the reference surfaces 24, 26 form aprimary angle A of 90° and a supplementary angle S of 90°. Therefore,there are 90 degrees of angular measuring capacity in this embodiment ofthe gauge 10. However, in an alternative embodiment, the gauge 10 may bedesigned so the wings 14, 16 may extend past the center pivot 18 formeasuring angles greater than 180°, or the total range of motion may berestricted to a total of 45 degrees effectively doubling the number ofangle settings available.

[0050] Setting an Angle

[0051] To set an angle between 90°-180°, the user simply locates thedesired angle (either A or S) on Table 1, reads the correspondingdistance D, and sets and locks the caliper arms 36, 38 at the distanceD. For example, assume a table saw blade must be positioned 135°relative to the table surface. The user simply refers to the chart tofind the distance D that corresponds to a 135° primary angle A andpositions and locks the caliper arms 36, 38 at that distance D (seeFIGS. 4 and 5). When the user positions one reference surface 24 flushwith the table, the other reference surface 26 will be set 135° relativeto the table surface (see FIG. 8). Thus, the user simply aligns the sawblade with reference surface 26 to ensure the blade is at a 135° anglerelative to the table surface. Alternatively, the 135° angle may be setusing the supplementary angle S of 45°.

[0052] Measuring an Angle

[0053] Similarly, to determine an angle between two workpiece or machinesurfaces, the user positions the reference surfaces 24, 26 of the gauge10 against the workpiece surfaces, reads the distance D off of thecaliper 40, and locates the corresponding angles A and S on Table 1(assuming the caliper 40 does not directly display the anglemeasurement). For example, to determine the angle between a table sawblade and the table, the user positions one reference surface 24 againstthe table and the other reference surface 26 against the saw blade (seeFIG. 8). The user then reads the distance D from the caliper 40 andconsults Table 1 to identify the angle A and S that correspond todistance D.

[0054] The angle gauge 10 embodiment of FIGS. 1-8 is limited to settingand measuring angles between 90° and 180°, inclusive. To expand themeasuring capabilities beyond a 90 degree range, a right angleattachment 60 may be added to the gauge 10, as shown in FIGS. 9 and 10.The right angle attachment 60 has an attachment reference surface 62 andis positioned along and secured to one of the wing reference surfaces24, 26. While any positioning and securing means may be used, FIGS. 9and 10 illustrate a dovetail recess in the foot 61 of attachment 60 sothe attachment 60 is simply slid onto the reference surface 24 structureof wing 14. The attachment 60 may be secured in place along the wingreference surface 24 with, for example, threaded screws 64 that passthrough foot 61 and bear against surface 24. The attachment 60 allowsthe user to measure and set obtuse angles by using the angle X (shown inFIG. 9) formed between the attachment reference surface 62 and the wingreference surface 26 not mounted with the attachment 60. The methods forsetting and determining angles are identical to those described above.FIG. 14 reproduces a portion of Table 2 that can be referenced todetermine corresponding linear and angular measurements when using asingle right angle attachment 60 with the angle gauge 10.

[0055] To measure acute angles more easily, a second right angleattachment 68 having a reference surface 70 is mounted on the secondwing 26 in a similar manner as the first right angle attachment 60. Anacute angle Y (see FIG. 11) between the reference surfaces 62, 70 of thefirst and second attachments 60, 68, respectively, can be set ormeasured by reference to Table 3 of FIG. 15, which reproducescorresponding linear and angular measurements when using two right angleattachments 60, 68 with the gauge 10.

[0056] FIGS. 16-24 show an alternative embodiment of the gauge 110 ofthis invention. Each wing 114, 116 includes two reference surfaces—aprimary reference surface 124, 126 and a secondary reference surface160, 162. As shown in FIGS. 19 and 21, when the wings 114, 116 arepivotally connected together, the secondary reference surfaces 160, 162intersect to form a small protractor angle B, and the primary referencesurfaces 124, 126 form a large protractor angle C, which is thecomplementary angle of the small protractor angle B. Each wing 114, 116may additionally be equipped with protuberances 164 and 166 that touchwhen gauge 110 is fully open (and caliper 140 is fully closed).

[0057] Gauge 110 may be attached to a dial or digital caliper 140 in thesame manner as gauge 10. When the caliper arms 136, 138 are in theirfully open position as shown in FIGS. 17-18 (i.e. D equals 6″), thesecondary reference surfaces 160, 162 are parallel and therefore form anangle B of 0°, and the primary reference surfaces 124, 126 form an angleC of 90°. When the caliper arms 136, 138 are in their fully closedposition as shown in FIGS. 19-20 (i.e. D equals 0″), the secondaryreference surfaces 160, 162 form an angle B of 90°, and the primaryreference surfaces 124, 126 are parallel and therefore form an angle Cof 0°. When so positioned, protuberances 164, 166 contact to prevent thewings 114, 116 from over-closing so that B is greater than 90°. However,in alternative embodiments, the wings 114, 116 may be formed to allowfor the primary 124, 126 and secondary reference surfaces 160, 162 toform angles greater than 90°. Moreover, the wings 114, 116 may also beformed to further restrict the angular measuring capacity of the gauge110 by, for example, preventing the maximum value of angle B or C fromexceeding 45°.

[0058] FIGS. 21-22 and 23-24 illustrate the protractor positioned toform an angle B of 45° and 66°, respectively, and an angle C of 45° and24°, respectively.

[0059] Gauge 110 is used in a manner similar to gauge 10. Gauge 110 isattached to the caliper arms 136, 138, and the caliper arms 136, 138translate along the caliper 140 to vary angles B and C. Table 4 (seeFIG. 25), similar to Tables 1-3, indicates the various angles B and Ccorresponding to a linear distance between the caliper arms 136, 138. Asan alternative or supplement to the table, a digital caliper or otherdevice may be programmed to calculate an angle from the linear distanceand display the angular value directly to the user.

[0060] The foregoing is provided for the purpose of illustrating,explaining and describing embodiments of the present invention. Furthermodifications and adaptations to these embodiments will be apparent tothose skilled in the art and may be made without departing from thespirit of the invention or the scope of the following claims. Forinstance, as is illustrated by comparing gauge embodiments 10 and 110,the principles of this invention may be practiced in different gaugeconfigurations. Attachment to a caliper is also not required; thecaliper could simply be used to measure the distance between a referencepin, surface or other structure on each of the gauge arms with the gaugeset at an unknown angle. Likewise, other gauge attachment structurescould be used, as could other pivot structures than those illustrated inthe drawings and described above. Gauge components can be molded, cast,extruded, machined or otherwise fabricated or formed of polymeric,metal, composite or other materials.

We claim:
 1. A measuring system comprising: a. a linear measuring devicefor measuring a linear distance; b. a protractor for forming at leastone angle, wherein the protractor is coupled to the linear measuringdevice; and c. conversion means for correlating the linear distance witha corresponding angular measurement of the at least one angle formed bythe protractor.
 2. The measuring system of claim 1, wherein the linearmeasuring device is a caliper.
 3. The measuring system of claim 1,wherein the protractor comprises at least a first wing and a second wingand the at least one angle comprises a first angle, wherein the firstwing and the second wing form the first angle and wherein the wings maybe pivoted relative to each other to vary the first angle.
 4. Themeasuring system of claim 3, wherein the first wing has a first wingreference surface and the second wing has a second wing referencesurface, wherein the first wing reference surface and the second wingreference surface are oriented at the first angle.
 5. The measuringsystem of claim 3, wherein the first wing and the second wing arepivotably connected.
 6. The measuring system of claim 4, wherein theprotractor further comprises a first attachment having a firstattachment reference surface, wherein the at least one angle comprises asecond angle and wherein the first attachment is positioned on the firstwing and the first attachment reference surface and the second wingreference surface form the second angle.
 7. The measuring system ofclaim 6, wherein the first attachment is positioned on the first wing atleast partially by a dovetail connection.
 8. The measuring system ofclaim 6, wherein the protractor further comprises a second attachmenthaving a second attachment reference surface, wherein the at least oneangle comprises a third angle and wherein the second attachment ispositioned on the second wing and the first attachment reference surfaceand the second attachment reference surface form the third angle.
 9. Themeasuring system of claim 8, wherein the second attachment is positionedon the second wing at least partially by a dovetail connection.
 10. Themeasuring system of claim 1, further comprising a coupling means,wherein the coupling means couples the protractor to the linearmeasuring device.
 11. The measuring system of claim 10, wherein thecoupling means comprises at least a first bracket arm and a secondbracket arm, wherein the first bracket arm is connected to the firstwing and the second bracket arm is connected to the second wing.
 12. Themeasuring system of claim 11, wherein the first bracket arm is pivotablyconnected to the first wing and the second bracket arm is pivotablyconnected to the second wing.
 13. The measuring system of claim 1,wherein the conversion means comprises at least one table.
 14. Themeasuring system of claim 1, wherein the conversion means comprises aconverting device programmed to convert the linear distance into thecorresponding angular measurement.
 15. The measuring system of claim 14,wherein the converting device is the linear measuring device.
 16. Themeasuring system of claim 15, wherein the converting device is a digitalcaliper.
 17. A measuring system comprising: a. a caliper comprising atleast a first arm and a second arm, wherein the caliper measures thelinear distance between the first arm and the second arm; b. aprotractor comprising a first wing and a second wing and at least oneangle formed by the first wing and the second wing, wherein the firstwing may be adjusted relative to the second wing to vary the at leastone angle and wherein the protractor is coupled to the caliper; and c.conversion means for converting the linear distance between the firstarm and the second arm into a corresponding angular measurement of theat least one angle.
 18. The measuring system of claim 17, wherein thecaliper is a digital caliper having a display screen.
 19. The measuringsystem of claim 18, wherein the conversion means comprises the digitalcaliper programmed to convert the linear distance into the correspondingangular measurement and to display the corresponding angular measurementon the display screen.
 20. A method for setting a desired anglecomprising: a. providing a protractor capable of forming at least oneangle and coupled to a linear measuring device for measuring a lineardistance; b. converting the desired angle into a desired lineardistance; and c. adjusting the linear measuring device to the desiredlinear distance so that at least one angle equals the desired angle. 21.A method for measuring a desired angle comprising: a. providing aprotractor comprising at least one angle and coupled to a linearmeasuring device for measuring a linear distance; b. adjusting the atleast one angle of the protractor to form the desired angle; and c.converting the linear distance of the linear measuring device into thevalue of the desired angle.
 22. An angle gauge comprising: a. a firstreference surface pivotably attached to a second reference surface; b. afirst bracket arm pivotably attached to the first reference surface andfor attachment to a caliper first arm; and c. a second bracket armpivotably attached to the second reference surface and for attachment toa caliper second arm.
 23. The gauge of claim 22, further comprising atleast one screw threaded into each bracket arm for attaching eachbracket arm to a corresponding caliper arm.
 24. The gauge of claim 22,further comprising a right angle attachment for attachment to one of thereference surfaces to provide a right angle reference surface positionedat a right angle to the reference surface to which it is attached.